But how about a 4C world? Consider some of the papers of a conference held in Oxford in late 2009. Take the time to review the papers, presentations and audio materials. Before anyone rushes to accuse me of alarmism, I’d like to state that models can contain a degree of uncertainty.

This is about probabilities: just like smoking increases the risk of lung cancer, continuing to emit CO2 at presents rates nudges us closer to a 4C world.

Jonathan, thanks for the link to your paper – I’ve started rading the paper and looking at your other resources. I like the multi-disciplinary approach and consideration of how CC will impact biology, ecology and human society.

You put the impact of temperature drops/rises into the right context:

“To put this 2 – 4 ºC warming window for the 21st century into context, the average global temperature was about 5 ºC or so cooler than 1990 during the depth of the last ice age (glacial). In short we will, over the next hundred years give or take a decade or two, warm the Earth by the same temperature difference as between now and the depth of the last ice age (glacial) some 25 thousand years ago!”

I find it incredible that many deniers continue to use the argument that “the Earth has always cooled/warmed”. True, no one is denying that. It’s the speed in which we are doing it that should be alarming.

Your conclusion is worth noting:

“Yes, there are these aforementioned threshold events. For example, one of these might be the warming of the oceans releasing methane from methane hydrates. Methane is a greenhouse gas that over a few decades is far more powerful than carbon dioxide. Another is that permafrosts, or peat lands, might be more sensitive to carbon dioxide release with warming than is thought. (For example some recent research(10) suggests that warming of just 1°C could result in northern, high-latitude peats losing 38 – 100 megatonnes of carbon a year (which is worth about 2.4- 6.3 billion Euros based on current carbon trading prices.)) Another could be that some tropical rain forests could be on the point of collapse with trees dying and in turn releasing their carbon into the atmosphere. Another might be that some ice fields (be they in west Antarctica or Greenland) might start melting a lot faster with only a little warming… You get the idea…”

Obviously sober thoughts. Have you read Clive Hamilton’s Requim for a Species?

Hamilton talks about the inevitability of a 2C (if not >4C) world. He takes the long view: climate change is now unavoidable, we should be getting ready for it’s inevitable consequences. He cautions againts “false hope”.

“exhortation and authority are not enough to solve the climate crisis — it is time for some humility!”

Haven’t we learned from RPJr that “facts” can be contaminated by scientists who don’t absolve themselves of the preference for one environmental outcome over another? We cannot trust the “facts” of scientists who prefer an environment consistent with human existence, over an environment consistent with a bug infested human-free heated marsh. A truly scientific mind must embrace total nihilism [oddly, no other actor in the debate is so required to handicap themselves…].

Quick, hook these alleged scientists to the RPjr “Humble-Meter”!

[/sarcasm]

The denialists have already realized that Bjorn is spent. After RPJr’s book is published, I will feel relief as he most assuredly flings himself off the same cliff.

I will thank Nature only after they go a few years without aiding the obscurantists.

Thanks for the links Manuel, indeed this is the exact dilemna we face. We can’t keep saying “Here are the facts, now act accordingly”. But RPjr’s piece is well… let me be polite and say his approach is not very helpful.